Potato virus M
Botanisches Institut, Universität des Saarlandes, 66 Saarbrücken, Germany
- Described by Schultz & Folsom (1923) and Bagnall, Larson & Walker
- Selected synonyms
- Kartoffel-K-Virus (Rev. appl. Mycol. 20: 486)
- Kartoffel-Rollmosaik-Virus (Rev. appl. Mycol. 15: 246)
- Potato interveinal mosaic virus (American) (McKay & Dykstra, 1932)
- Potato leaf rolling mosaic virus (Rev. appl. Mycol. 3: 548)
- Potato paracrinkle virus (Rev. appl. Mycol. 9: 604)
- Potato virus E (Rev. appl. Mycol. 12: 776; 18: 337)
- Solanum virus 7 (Rev. appl. Mycol. 36: 303)
- Solanum virus 11 (Rev. appl. Mycol. 36: 303)
- A virus with straight to slightly curved filamentous particles c.
650 x 12 nm. It is sap-transmissible to a limited range of species. Most
isolates are transmitted by aphids in the non-persistent manner. World-wide
In potato, symptoms range from very slight (e.g.
cv. King Edward)
to severe (e.g.
cv. Arran Victory), depending on virus strain and potato
variety. Causes various mottle, mosaic, crinkling and rolling symptoms in leaves,
and stunting of shoots (Fig.1
World-wide in cultivated varieties of potato.
Host Range and Symptomatology
Host range is narrow. Susceptible species belong mainly to the Solanaceae.
Transmissible by inoculation with sap from young leaves, but not from older leaves.
May be transmitted from potato to potato by grafting.
- Diagnostic species
- Datura metel. Chlorotic or necrotic local lesions in inoculated leaves
(Fig.2). Systemically infected leaves show rugosity and chlorotic spotting.
First the lower leaves, later the upper ones are shed, and the plants become
stunted and sometimes die.
- Gomphrena globosa. Some isolates from mainland Europe cause local
chlorotic spots surrounded by reddish borders (Fig.3).
- Lycopersicon esculentum (tomato). Systemically infected, but
- Nicotiana debneyi. Irregular brown necrotic ring-like local lesions
(Fig.4). Not systemic.
- Solanum rostratum. Necrotic streak of stem, petioles and leaf-veins;
- Propagation species
- Lycopersicon esculentum. Young leaves are a suitable source of virus
- Solanum tuberosum. cv. Saco may be used to maintain the virus.
- Assay species
- Datura metel and Gomphrena globosa are local lesion hosts. When
potato sap is used as inoculum, the number of local lesions on both hosts
increases if the sap is heated at 50°C for 10 min.
- Phaseolus vulgaris
(Red Kidney bean) is reportedly a useful local lesion host (Hiruki, 1970).
Several variants can be distinguished by the symptoms they induce in potato
and by slightly differing symptoms in test plants. The best known variants are:
Leaf rolling mosaic and interveinal mosaic isolates (Schultz
& Folsom, 1923; Bagnall et al., 1956).
Paracrinkle isolate from potato cv. King Edward (Salaman & Le
Pelley, 1930; Kassanis, 1961).
D 1102 and Fortuna isolates (Köhler, 1953; Wetter &
Dutch isolates (Rozendaal & Van Slogteren, 1958).
Transmission by Vectors
Transmissible in the non-persistent manner by the aphid Myzus persicae
(Wetter & VöIk, 1960
); less efficiently by Aphis frangulae, A.
and Macrosiphum euphorbiae
(Bode & Weidemann, 1970
The potato paracrinkle virus present in the Rothamsted stock of King Edward is
not aphid-transmitted (Kassanis, 1961
Transmission through Seed
Transmission by Dodder
The virus is a good immunogen. Antisera with titres of 1/8000 were obtained
by primary intravenous injections of partially purified virus preparations
followed by injections with antigen in Freund's complete or incomplete adjuvant
). The precipitate in precipitin tube tests is flagellar.
Serological tests are the best way of diagnosing the virus in potato. Several
kinds of test have been used in diagnosis of infection in potato: the
microprecipitin (Van Slogteren, 1955
), slide precipitin (Wetter, 1960
bentonite flocculation (Kahn et al., 1967
) tests. To detect the virus in
the presence of the related potato virus S
, antisera against potato virus M
absorbed with potato virus S can be used (Bagnall, Wetter & Larson, 1959
Double diffusion tests in agar gel can be used, but a high concentration of
antigen is necessary (Wetter, 1967
Potato virus M is distantly serologically related to the following viruses which
together form the carnation latent virus
) group (Harrison et al.,
): carnation latent (Kassanis, 1955
), potato S
(Bagnall et al.,
), chrysanthemum B
(Hakkaart, Van Slogteren & De Vos, 1962
passiflora latent (Brandes & Wetter, 1963
), cactus 2 (Brandes & Wetter,
) and red clover vein mosaic
Most potato varieties infected with potato virus M also contain potato virus S.
No cross-protection was observed between these two viruses, which share only a
few antigenic groups. In mixed infections, symptom expression in potato depends
on the virulence of the potato virus M isolate (Howard & Wainwright, 1960).
Stability in Sap
Thermal inactivation point is 65-71°C, dilution end-point is
and infectivity is retained at 20°C for
. Extract sap from infected tomato or potato leaves and add
ascorbic acid to 0.2% (w/v) and sodium sulphite to 0.2% (w/v). Filter, and shake
filtrate with an equal volume of ether. Centrifuge, then shake clarified aqueous
phase with an equal volume of carbon tetrachloride. Sediment and clarify by two
cycles of high and low speed centrifugation, resuspending the pellets in 0.01 M
phosphate buffer. Density gradient centrifugation can be used for further
Properties of Particles
No reports; probably similar to carnation latent virus
Particles are straight to slightly curved filaments c.
650 x 12 nm
(Brandes et al., 1959
). Very probably they are helically
constructed as described for other members of the carlavirus
group (Varma et al.,
Relations with Cells and Tissues
In potato and tomato tissue X-bodies but no crystalline inclusions were
observed by light microscopy (C. Wetter, unpublished). Infected potato can be
freed from potato virus M and potato virus S
by apical meristem culture as demonstrated
for the potato variety King Edward (Kassanis, 1957
Potato virus M is accompanied in most potato varieties by the more widespread
potato virus S
. It can be separated from the latter by inoculation to tomato
which is immune to potato virus S. The potato variety Saco, which is highly
resistant to potato virus S and potato virus X
, can also be used for separation.
- Bagnall, Larson & Walker, Res. Bull. agric. Exp. Stn Univ. Wis. 198, 45 pp., 1956.
- Bagnall, Wetter & Larson, Phytopathology 49: 435, 1959.
- Bode & Weidemann, Proc. 4th trienn. Conf. Eur. Ass. Potato Res. Brest 1969: 224, 1970.
- Brandes & Wetter, Phytopath. Z. 49: 61, 1963.
- Brandes, Wetter, Bagnall & Larson, Phytopathology 49: 443, 1959.
- Hakkaart, Van Slogteren & De Vos, Tijdschr. PlZiekt. 68: 126, 1962.
- Harrison, Finch, Gibbs, Hollings, Shepherd, Valenta & Wetter, Virology 45: 356, 1971.
- Hiruki, Phytopathology 60: 739, 1970.
- Howard & Wainwright, Nature, Lond. 186: 993, 1960.
- Kahn, Scott, Bozicevich & Vincent, Phytopathology 57: 61, 1967.
- Kassanis, Ann. appl. Biol. 43: 103, 1955.
- Kassanis, J. gen. Microbiol. 15: 620, 1956.
- Kassanis, Ann. appl. Biol. 45: 422, 1957.
- Kassanis, Eur. Potato J. 4: 13, 1961.
- Köhler, Ber. dt. bot. Ges. 66: 63, 1953.
- McKay & Dykstra, Bull. Ore. agric. Exp. Stn 294, 1, 1932.
- Rozendaal & Van Slogteren, Proc. 3rd Conf. Potato Virus Diseases, Lisse-Wageningen 1957: 20, 1958.
- Salaman & Le Pelley, Proc. R. Soc. B 106: 140, 1930.
- Schultz & Folsom, J. agric. Res. 25: 43, 1923.
- Van Slogteren, Proc. 2nd Conf. Potato Virus Diseases, Lisse-Wageningen, 1954: 51, 1955.
- Varma, Gibbs, Woods & Finch, J. gen. Virol. 2: 107, 1968.
- Wetter, Arch. Mikrobiol. 37: 278, 1960.
- Wetter, Z. Naturf. B 22: 1008, 1967.
- Wetter & Brandes, Phytopath. Z. 26: 81, 1956.
- Wetter & Völk, Eur. Potato J. 3: 158, 1960.
The support of the Wissenschaftliche Gesellschaft des Saarlandes is
Systemic symptoms in shoots of potato cv. Arran Victory infected
with the paracrinkle isolate from King Edward. (Left) primary infection,
(centre) secondary infection, (right) healthy.
Local lesions in Datura metel induced by the D 1102 isolate.
Local lesions in Gomphrena globosa induced by the Fortuna
Local necrotic rings in Nicotiana debneyi induced by the
interveinal mosaic isolate.
Virus particles from a leaf dip preparation. Bar represents 500 nm
(courtesy of the late Dr J. Brandes).